BirdAnalyst
Species · BCR 11 · BBS 2026 Release · 1966–2025

Tree Swallow In Prairie Potholes

All regionsPrairie PotholesAerial insectivores

Tree Swallow in Prairie Potholes has surged: up 520% on the route-weighted index since 1969.

+520%Since 1969TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
112Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Tree Swallow has surged in Prairie Potholes: up 520% on the route-weighted index since 1969.

Tree Swallow In Prairie Potholes Population Forecast

If the recent trend holds, Tree Swallow in Prairie Potholes is projected to rise about 179% by 2030 — from 1.8 in 2025 to a central estimate of 5.1 (95% range 3.0–7.1). A 5-year backtest shows a typical error of ±93.1%, with 0% of held-out values landing inside the 95% band.

+179%Change by 2030TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
5.1Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
3.0–7.195% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±93.1%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Tree Swallow in Prairie Potholes is projected to rise about 179% by 2030 — from 1.8 in 2025 to a central estimate of 5.1 (95% range 3.0–7.1). A 5-year backtest shows a typical error of ±93.1%, with 0% of held-out values landing inside the 95% band.19672030
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20264.82.76.8
20274.82.86.9
20284.92.96.9
20295.03.07.0
20305.13.07.1

Routes In Prairie Potholes

Routes recording Tree Swallow in Prairie Potholes.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
ParshallNORTH-DAKOTA1052011
LennoxSOUTH-DAKOTA132023
TurtonSOUTH-DAKOTA132023
ChokioMINNESOTA92025
TylerMINNESOTA92025
WalcottNORTH-DAKOTA82023
EdgeleyNORTH-DAKOTA82025
BurchinalIOWA72024
AppletonMINNESOTA72025
TenneyMINNESOTA72016
BeltramiMINNESOTA72025
Big StoneMINNESOTA72012
Eagle CreekNEBRASKA72023
AbercrombieNORTH-DAKOTA72012
MaynardMINNESOTA62015
GluekMINNESOTA62019
ErieMINNESOTA62015
Chokio NorthMINNESOTA62025
LockhartMINNESOTA62024
RollaNORTH-DAKOTA62024
CarpioNORTH-DAKOTA62023
RoswellSOUTH-DAKOTA62014
DawsonMINNESOTA52025
TracyMINNESOTA52025
DanzigNORTH-DAKOTA52014

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.